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Experimental and numerical analysis of a novel constructal design for canopy-to-canopy liquid cooling systems
Get PDFThe cooling capacity of canopy-to-canopy flat plates with the coolant inlet and outlet on the same side of the plate was analyzed in detail, both experimentally and numerically. A novel constructal design was proposed to derive the diameter of each branch of canopy-to-canopy configurations. Thanks to the predicted diameter ratios, the new design results in a reduction of the coolant pumping power of 60 % to achieve the same maximum temperature as a traditional configuration with equal diameters in all branches. Four canopy-to-canopy configurations with a number of branches ranging from 2 to 5 were designed based on this innovative constructal approach to optimize the cooling capacity of flat plate systems, keeping the same fluid volume for all of them. The resulting designs were tested experimentally and modelled for steady state and transient cooling operations. A higher number of branches improved the steady state cooling performance under continuous heating, as the 5-branches configuration yielded the lowest maximum and mean temperatures while maintaining similar temperature homogeneity in both experimental measurements and numerical simulations. The maximum deviation between experimental and numerical results was 1.4 °C for both maximum and average temperatures, allowing the validation of the numerical models. For the transient cooling process, the flat plates experienced a progressively faster temperature reduction over time as the number of branches in the design increases, accelerating the cooling process by 14.7 % when increasing the number of branches from 2 to 5. The results show that the 5-branches canopy-to-canopy configuration has an excellent cooling capacity with a limited pressure drop to circulate the coolant.This work has been supported by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M (EVIACOOL-CM-UC3M), and the grants “Ayudas para la Formación de Profesorado Universitario” (FPU21/02952) and “Ayudas complementarias de movilidad para beneficiarios de ayudas FPU” (EST23/00388) awarded by the Spanish Ministry of Universities
Low-frequency oscillations in the magnetic nozzle of a Helicon plasma thruster
Get PDFOscillations within the plume of a Helicon plasma thruster are experimentally characterized. An array of electrically-floating probes is used to resolve the power spectral density, the coherence, and the wavevector components along both the azimuthal and parallel directions relative to the magnetic field, at various locations and for two mass flow rates. Two main features are identified: a very low-frequency (≃4 kHz), global oscillation mode, attributed to an ionization instability in the source; and a broadband, low-coherence, essentially-azimuthal, ion-acoustic-like spectrum at <200 kHz. Within this range, a mild peak of larger coherence is found at ≃50 kHz, followed by a weak secondary peak at ≃100 kHz at some locations. A bi-coherence analysis discards any nonlinear interaction within the <1 MHz band. However, significant coupling is found between the broadband fluctuations and the Helicon driving frequency of 13.56 MHz, which suggests that the former are likely the result of a parametric
decay instability.This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project ERC-STG ZARATHUSTRA, Grant Agreement No. 950466). Additionally, F Terragni was also supported by the FEDER / Ministerio de Ciencia, Innovación y Universidades—Agencia Estatal de Investigación (Grant Agreement No. PID2020-112796RB-C22), while B Bayón-Buján enjoyed a grant from the Consejería de Educación, Universidades, Ciencia y Portavocía of the Community of Madrid (Grant PEJ-2021-AI/TIC-23158)
Resistencia de materiales: problemas resueltos
Get PDFEste libro consta de una colección de problemas resueltos, sobre Resistencia de Materiales. Se compone de cuatro capítulos, los cuales abordan problemas de cálculo de esfuerzos internos, desplazamientos y giros en vigas continuas isostáticas e hiperestáticas, en vigas sometidas a torsión, estructuras articuladas, y reticuladas, empleando diferentes herramientas y métodos de resolución. Además, incluye un formulario de desplazamientos, giros y reacciones para vigas con configuraciones sencillas
Tradición, memoria y progreso: retos actuales de la universidad desde la historia: XV Congreso Internacional sobre Historia de las Universidades
Get PDFActas del XV Congreso Internacional sobre Historia de las Universidades, 20-21 Nov. 2024, ValenciaEn el salón de grados “Ascensión Chirivella” de la facultat de dret de València, los días 20 y 21 de noviembre de 2024 se celebró el XV Congreso Internacional sobre Historia de las Universidades, dedicado en esta ocasión a los “Retos actuales desde la historia”. Las ponencias se desarrollaron en nueve mesas temáticas. Se publican ahora las actas de esa reunión científica, que ofrecen (ordenados alfabéticamente) 36 estudios elaborados por 38 investigadores.Edición financiada por el Programa Prometeo 2022 (CIPROM/2021/028)VOLUMEN 1: La creación del Colegio Universitario de Castellón / Ramon Aznar i Garcia (pp. 9-38). -- Desarrollismo y antifranquismo en la facultad de Filosofía y Letras de Valencia, 1965-1975 / Marc Baldó Lacomba (pp. 39-74). -- La construcción de bases de datos como instrumentos para la investigación sobre Historia de las Universidades. La red europea HÈLOÏSE / Manuel Ángel Bermejo Castrillo (pp. 75-96). -- Aurora Arnaiz Amigo (1913-2009), una profesora de derecho en el exilio / Yolanda Blasco Gil, Armando Pavón Romero (pp. 97-124). -- Fray Francisco Gavaldá, catedrático del Estudi General de Valencia / Emilio Callado Estela (pp. 125-154). -- Mediodía del derecho. Profesorado (y algunos alumnos) de la Facultad de Derecho de la Universidad de Sevilla en las primeras décadas del siglo XX hasta la Guerra Civil: un acercamiento histórico a la cultura universitaria sevillana / Alfonso Castro Sáenz (pp. 155-230). -- América, su historia, en la UJI / Manuel Chust, Cristina Fonseca Ramírez (pp. 231-252). -- Los catedráticos de Derecho Político de Valencia durante el primer franquismo (1939-1959), con especial referencia a Tomás Elorrieta y Artaza / Irene Climent Campos (pp. 253-280). -- El conde palatino Pere Antoni Beuter (c. 1490-1554), y los cuestionados grados pontificios en la Universidad de Valencia de mediados del siglo XVI / Manuel Vte. Febrer Romaguera (pp. 281-324). -- La mujer y la carrera de derecho. Especial referencia a las primeras licenciadas y doctoras de derecho por Valencia / Pilar García Trobat (pp. 325-370). -- Scholars from Spain and Portugal at Universities in the Holy Roman Empire (1250-1550). Perspectives and Results from Digital History / Kaspar Gubler (pp. 371-408). -- Status, condizione economica e mobilita’ dei lettori (secoli XVI-XVIII). Mondo spagnolo e italiano a confronto / Maria Teresa Guerrini (pp. 409-424). -- Los estudios jurídicos y la educación preuniversitaria / Celia Hernández Cañete (pp. 425-462). -- Los años sesenta en la Facultad de Derecho de Valencia: nuevo plan y nueva sede / María Pilar Hernando Serra (pp. 463-506). -- El frustrado proyecto de crear una Universidad Católica en Pamplona en los primeros meses de la Guerra Civil (otoño de 1936) / Roldán Jimeno Aranguren (pp. 507-540). -- Omnis definitio est periculosa: Las discusiones del Institut de Droit International sobre el principio de ocupación efectiva tras la Conferencia de Berlín (1884-1908) / Pedro López Herraiz (pp. 541-574). -- VOLUMEN 2: Arxius universitaris i investigació / Mª Irene Manclús Cuñat (pp. 11-18). -- El modelo de universidad residencial en la España del siglo XX / Manuel Martínez Neira (pp. 19-44). -- Professori di diritto e corrispondenze accademiche. Mario Rotondi (1900-1984) e i cattedratici spagnoli nel secondo Novecento / Annamaria Monti (pp. 45-64). -- Notas sobre la creación de la Universidad Miguel Hernández de Elche / Sara Moreno Tejada (pp. 65-90). -- L’università italiana vista e vissuta da Giovanni Battista Montini agli inizi del XIX secolo / Simona Negruzzo (pp. 91-128). -- La carrera académica en la LOSU y la distribución de contratos predoctorales de formación del profesorado universitario por ramas del conocimiento. Sesgos y amenazas para el Derecho y las ciencias sociales / Javier Palao Gil (pp. 129-166). -- El archivo universitario, transformación digital e historia de las universidades / Lidón París-Folch (pp. 167-180). -- Instrumentos para la historia de las facultades de Derecho. Un informe de investigación / Carlos Petit (pp. 181-196). -- La Universidad de Cervera: realidad y mito. Más allá de los tópicos y las valoraciones interesadas / Joaquín Prats Cuevas (pp. 197-224). -- Primeras cátedras de derecho del trabajo en la Facultad de Derecho de la Universidad de Valencia / Mario Francisco Quirós Soro (pp. 225-244). -- Las cátedras de Concilio de Trento y el derecho catalán / Rafael Ramis Barceló (pp. 245-260). -- El Centre de Cultura Valenciana. Els seus vincles amb la Universitat de València (1915-1931) / Joan Ramon i Alcaide (pp. 261-294). -- Salamanca 1898-1923. Una universidad mortecina / Luis E. Rodríguez-San Pedro Bezares (pp. 295-306). -- Fadrique Furio Ceriol. El valenciano que planifica el “buen gobierno” laico con siglos de antelación / Remedio Sánchez Ferriz (pp. 307-324). -- José Martínez Gijón, alma y fundador de la Historia del Derecho mercantil en la universidad española del siglo XX / Margarita Serna Vallejo (pp. 325-372). -- De la cátedra a oficial real: Lorenzo de Santanya en la administración borbónica / Mónica Soria Moya (pp. 373-406). -- Explicar las Leyes de Toro en el siglo XIX: acerca de unos comentarios manuscritos procedentes de la Universidad de Salamanca / Eugenia Torijano Pérez (pp. 407-418). -- Poder sin letras, audiencia sin universidad; entre Buenos Aires y Córdoba del Tucumán / Carlos Tormo Camallonga (pp. 419-456). -- Realidad y utopía de la universidad española del ministro José Ibáñez Martín (1939-1951) / Carlos Veci Lavín (pp. 457-486). -- Movilidad universitaria y democracia. Facultad de Derecho de Valencia (1976-1979) / Sergio Villamarín Gómez (pp. 487-514
Predicting electricity supply and demand curves with functional data techniques
Get PDFThe profitability of electricity companies in Europe, especially in Spain, has been declining due to the poor performance of liberalized activities (generation and commercialization). This decline is caused by reduced demand, decreased investment, and asset value loss from the economy's decarbonization. In this context, precise forecasts of hourly supply and demand curves, as well as hourly prices in the wholesale electricity market, are crucial for optimizing energy buying and selling strategies. This work focuses on the daily Spanish spot market, where energy is traded for the 24 h of the following day. This market is crucial as it accounts for the highest volume of energy traded, contributing the most to the final electricity price (88.7% in 2023, according to the Spanish System Operator). Optimizing strategies in this market can significantly improve participants' economic outcomes. Despite extensive study, there is still room for improvement. This paper proposes predicting hourly supply and demand curves and the matching price and matching energy for the following day using various functional analysis techniques. It combines functional analysis and machine learning techniques, incorporates seasonal and regular lags due to the strong dependency found between consecutive hours, and includes meteorological information from eight variables across Spanish provinces. Additionally, we do not assume smooth curves, leading to more realistic predictions. Finally, predictions are adjusted with the closest training set curve. The extensive backtesting results highlight the importance of considering all these aspects to reduce prediction errors for curves and hourly prices and energies.The authors gratefully acknowledge financial support from the Spanish government through the Ministry of Science and Innovation projects PID2019-108311GB-I00 and PID2022-138114NB-I00. A.M. Alonso also acknowledges the funding by Grant PID2023-151013NB-I00, funded by MCIN/AEI/10.13039/501100011033 and by FEDER/UE
Billion-Scale Expansion of Functional hiPSC-Derived Cardiomyocytes in Bioreactors Through Oxygen Control and Continuous Wnt Activation
Get PDFGeneration of upscaled quantities of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM), for therapeutic or testing applications, is both expensive and time-consuming. Herein, a scalable bioprocess for hiPSC-CM expansion in stirred-tank bioreactors (STB) is developed. By combining the continuous activation of the Wnt pathway, through perfusion of CHIR99021, within a mild hypoxia environment, the expansion of hiPSC-CM as aggregates is maximized, reaching 4 billion of pure hiPSC-CM in 2L STB. In particular, the importance of i) controlling the dissolved oxygen at 10% O2 to reduce reactive oxygen species production and upregulate genes involved in cell proliferation, resulting in higher expansion rates (tenfold) compared to normoxic conditions, and ii) maintaining constant power input per volume as a scale-up criteria is demonstrated. After expansion, hiPSC-CM further mature in culture, revealing more mature transcriptional signatures, higher sarcomere alignment and improved calcium handling. This new bioprocess opens the door to time- and cost-effective generation of hiPSC-CM.The authors acknowledge A.L. Sousa and E.M. Tranfield from the Electron Microscopy Facility at the IGC for the transmission electron microscopy work. This work was supported by the European Union Horizon 2020 program through project BRAV3 (ID: 874827) and by Fundação para a Ciência e a Tecnologia (FCT) through project EXCELERATE (DOI 10.54499/2022.10467.PTDC). This work was also funded by FCT/Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES, Portugal) through national funds to iNOVA4Health (UIDB/04462/2020 and UIDP/04462/2020) and the Associate Laboratory LS4FUTURE (LA/P/0087/2020), Interreg SUDOE under CardioPatch (SOE4/P1/E1063) and Ministerio de Ciencia, Innovación y Universidades CARDIOPRINT (PLEC2021-008127), VOLVAD (PID2022-142562OB-I00) and INVESTTRA (PID2022-142807OA-I00) funded by MICIU/AEI /10.13039/501100011033 and by the European Union NextGenerationEU/PRTR, Gobierno de Navarra Proyectos Colaborativos BIOGEN (PC020-021-022). P.V. was supported by FCT fellowships SFRH/BD/145767/2019. A.U.-A. was supported by a Sara Borrell grant (CD22/00027) from the Instituto Carlos III and NextGenerationEU. Figures 1, 2, 5A and 6A were created with Biorender.com
Cartografía de la edición académica en 16 países de América Latina entre 2013 y 2019
No full textPrograma de Doctorado en Documentación: Archivos y Bibliotecas en el Entorno Digital por la Universidad Carlos III de MadridPresidenta: María Luisa Lascuraín Sánchez.- Secretario: Evaristo Jiménez Contreras.- Vocal: Elba Margarita Sánchez Roló
Imprinto: Enhancing Infrared Inkjet Watermarking for Human and Machine Perception
Get PDFProceedings of: CHI 2025: CHI Conference on Human Factors in Computing Systems , Yokohama (Japan), 26 April 2025- 1 May 2025Hybrid paper interfaces leverage augmented reality to combine the desired tangibility of paper documents with the affordances of interactive digital media. Typically, virtual content can be embedded through direct links (e.g., QR codes); however, this impacts the aesthetics of the paper print and limits the available visual content space. To address this problem, we present Imprinto, an infrared inkjet watermarking technique that allows for invisible content embeddings only by using off-the-shelf IR inks and a camera. Imprinto was established through a psychophysical experiment, studying how much IR ink can be used while remaining invisible to users regardless of background color. We demonstrate that we can detect invisible IR content through our machine learning pipeline, and we developed an authoring tool that optimizes the amount of IR ink on the color regions of an input document for machine and human detectability. Finally, we demonstrate several applications, including augmenting paper documents and objects
Dual luminescent nano-thermometry based on the selective excitation of optical centers in CaF2:Er3+ nanoparticles
Get PDFWe present a study about the feasibility of using the upconverted luminescence of CaF2:Er3+ nanoparticles (NPs), under near infrared excitation within the 4I15/2 → 4I11/2 absorption band, for thermal detection. In order to perform this study, it has been needed to investigate the upconversion processes as function of the Er3+ con-centration and the excitation wavelength by using a tunable Ti:Sapphire laser. The results obtained indicate that, under this excitation scheme, the green (2H11/2:4S3/2) and red (4F9/2) emitting levels are populated through different multiphoton processes: Excited state absorption and energy transfer upconversion. Therefore, the ratio between the green and red emissions is also dependent on the Er3+ concentration and the excitation wavelength. Measurements based on site-selective emission/excitation, performed at room temperature, indicate that in these NPs there are at least two different optical centers whose emission bands can be isolated by an appropriate selection of the excitation wavelength. One these centers is compatible with the presence of isolated Er3+ ions, while the other one is tentatively related to the presence of clusters or aggregates. The upconverted luminescence of each optical center is analyzed as function of temperature by means of the ratiometric Fluorescence Intensity Ratio technique. The results indicate that both optical centers exhibit adequate thermal performances and relative sensitivities to be used in thermal sensing.This work has been partially supported by Ministerio de Ciencia e Innovación (Spain) under project COLUMNAS (PID2019-110632RB-I00)
